1. Field of the Invention
The present invention relates to tolerance rings and more particularly to means for retaining the tolerance ring axially and/or angularly with respect to an abutting surface.
2. Description of the Prior Art
Tolerance rings are generally formed as split ring members having a corrugated surface and are sandwiched between two cylindrical surfaces, that is, an outer cylindrical surface and an inner cylindrical surface, to provide frictional engagement between two members having the respective cylindrical surfaces. The corrugations on the ring may protrude inwardly from an outer surface thereof, outwardly from an inner surface thereof or alternatively inwardly and outwardly. Such tolerance rings are illustrated in U.S. Pat. Nos. 3,142,887 and 3,145,547. The corrugations on the tolerance rings may be of varying heights or may be arranged in more than one row around the circumference of the ring as is illustrated in U.S. Pat. Nos. 3,700,271; 3,838,928 and 4,286,894.
U.S. Pat. No. 3,061,386 discloses a tolerance ring in which the adjacent ends of the transversely split ring are bent inwardly to form butt portions 14, presumably to prevent overlap of the adjacent ends of the ring.
U.S. Pat. No. 2,931,412 discloses a corrugated spring steel bushing in which the corrugations are provided along the entire axial length of the bushing and a stop flange 17 is provided at one end of the bushing, formed after the corrugations have been formed in the length of the bushing. Thus, the stop flange 17 includes the corrugations. A bearing sleeve 11 is provided which is inserted into the bushing 16, and the bearing sleeve 11 has an axial key 13 which engages in an inner groove formed by the corrugations of the locking sleeve to prevent the bearing sleeve 11 from rotating relative to the bushing 16.
When tolerance rings are used in some applications, particularly vertical orientations, where the axis of the ring is vertical, and where there is sufficient vibration, there may be a tendency for the tolerance ring to "walk" out of its position in an axial direction. If the tolerance ring were to completely "walk" out of its original position, frictional engagement between the two members would be greatly reduced, thus resulting in a loss of torque transfer between the members, misalignment of the members, etc.
Also, in some instances during repair and replacement work on the parts joined by tolerance rings, the cylindrical surfaces engaged by the rings may be inadvertently or intentionally changed in size slightly causing a looser fit of the ring than is specified. In such instances, the tendency for the ring to "walk" in an axial direction is enhanced.
These instances result in undesirable axial movement of the ring. Efforts to solve this problem in the past have been to modify the parts engaged by the rings to add lips or to peen over edges of the openings into which the rings are inserted, causing additional expense and having problematical results.
Similarly, the rings may be subject to some rotational slippage when sandwiched between two rotating parts if vibration is sufficiently great or if the sizes of the cylindrical surfaces are out of the specified ranges.
Therefore, it would be an advantageous development if there were a means to inexpensively and assuredly prevent the tolerance rings from moving axially and/or rotationally from their intended positions.